Dissipation kinetics, pre-harvest residue limits, and dietary risk assessment of the systemic fungicide metalaxyl in Swiss chard grown under greenhouse conditions


Kabir M. H., Abd El-Aty A. M., Rahman M. M., Chung H. S., Lee H. S., Jeong J. H., ...Daha Fazla

REGULATORY TOXICOLOGY AND PHARMACOLOGY, cilt.92, ss.201-206, 2018 (SCI-Expanded) identifier identifier identifier

Özet

The residual behavior of the systemic fungicide, metalaxyl, in Swiss chard cultivated at two different locations under greenhouse conditions was investigated using high-performance liquid chromatography coupled with an ultraviolet detector (HPLC-UVD). Samples were randomly collected over 14 days and extracted using acetonitrile, partitioned using solid sodium chloride, and a solid-phase extraction (SPE) NH2 cartridge was used for cleanup. The linearity over a concentration range 0.05-50 mg/L was excellent with a coefficient of determination (R-2) of 0.9997. The recovery rate ranged from 77.05 to 88.92% with relative standard deviations (RSDs) <= 10.74, and the limits of detection (LOD) and quantification (LOQ) were 0.0033 and 0.01 mg/kg, respectively. The initial (2 h after application) deposits were 4.69 and 5.90 mg/kg for sites 1 and 2, respectively, which increased to 4.95 and 6.57 mg/kg, respectively, one day post-application, owing to the systemic properties of the fungicide. The dissipation half-life was 5.3 and 6.0 days for sites 1 and 2, respectively. The pre-harvest residue limit (PHRL) suggested that if 55.38 and 47.23 mg/kg was applied 10 days before harvest or 33.28 and 30.73 mg/kg was applied 5 days before harvest (for sites 1 and 2, respectively) then the concentration will fall below the maximum residue limit (MRL = 20.0 mg/kg) at the time of harvest. The dietary risk assessment, estimated as hazard quotient (RQ%), indicate that metalaxyl can be safely used in/on Swiss chard, with no hazardous effects expected for consumers.